Flood watch posted for mid-Missouri

A flash flood watch was posted for Boone County through Thursday evening, and a Weather Service forecaster said rainfall could total 4 inches or more.

“A conservative estimate is 2 to 3 inches by Thursday afternoon and an additional 1.5 to 2 inches by Friday,” Jon Carney of the National Weather Service in St. Louis.

Flood watches were in effect for a wide swath of Missouri from the southwest to the northeast, with the heaviest rain in the Columbia area expected Wednesday night into Thursday morning.

The flood threat is being caused by a cold front in northern Missouri that is dropping south and interacting with an upper level disturbance moving north from the southern Plains.

“There will be steady showers and thunderstorms ongoing, with periods of very heavy rain that we are worried about, and it may not stop until Friday evening,” Carney said. “The air is just unusually moist.”

Any thunderstorms that develop probably won’t be severe. “Severe weather needs dry and cool air, and we don’t have that right now. So we aren’t that worried about tornadoes or other severe weather,” Carney said. “Besides the chance of a little hail, it is just going to primarily be heavy rain.”

Tommy Sallee of the Missouri Agriculture Statistics office said farmers need the rain.

“How fast it comes down is what matters,” Sallee said. “It if comes down too hard, it all runs off. We need a long, gentle soaking rain. Four to five inches of rain wouldn’t hurt us.”

Rainfall in Columbia this year through Wednesday afternoon totaled 14.88 inches, 4.94 inches below the average of 19.82.